Thank you all for your replies. They are helpful and have given me food for thought about tackling the issue with the school.
The pushing games are of a concern and I don't understand it myself. I suspect that they are not actually "allowed" but possibly just not policed. I did wonder whether the game they play, "Duck, Duck, Goose," descends into a "pushing game" amongst children who are still very young.
vegansrock, I understand what you are saying and all forms of education were considered for my DGS. He was observed within the nursery setting and it was noted that he followed the other children with the tasks set (even though he was non-verbal) and he followed their behaviours too. It was felt that if he went to an SEN school, where the children are very often in their own little world/non-verbal/struggling socially and not responding enthusiastically, he would not have role models to learn from. He is now speaking in sentences, some of which I understand(!) and has come such a long way, from a learning point of view, he is in the wrong place. I suspect that he will be a little bit of a square peg in a round hole wherever he goes.
We have been very happy with the way the children within the school have been inclusive, he has been to so many parties. He has made a particular friend who he meets outside of school and his mother, who is very shy, has found a friend too so it it has been really good for them.
My son has been really straight with the school about knowing the worst of any issues and needing full transparency. He doesn't want to have to read between the lines, he wants to be able to work with his son on any issues. I think I will advise him to be transparent with the school about how this is going to affect his child as he gets more aware and ask the school to address it.
As to the entertainer, an opportunity to educate was missed but my son will be ready to tackle this on future occasions.
When my children were younger they were rather dumbfounded by the entertainer who talked about rowing parents and argumentative siblings in the journey there. We didn't row or bicker in front of them and they sang hymns (atheist husband somewhat bemused) or played games on the way. We just wouldn't have let them argue or fight. They were also horrified by the continued use of the word, "Shut-up". I wouldn't let them use it, "Be quiet," was quite adequate!!!